I did some math, supposedly the complete install of the latest Call of Duty game is a 200GB download[0]. At 1gbps we're talking 26 minutes of downloading. At 2.5gbps we're talking 10 minutes of downloading. I'm honestly surprised game downloads have become so massive but are those 16 extra minutes really going to change anything?

Personally, I'm rarely "surprised" by a need to play a specific game that I don't already have downloaded/installed so I can just tell Steam to download the game in advance. But if I were to be in such a surprise scenario, we're talking the difference between popping on one youtube video while I wait or popping on two youtube videos while I wait. In both scenarios, I am waiting for a small but not insignificant amount of time... now if we could get 10gbps that'd be a game changer. I wouldn't even context switch for a 2.6 minute wait.

[0] https://gameboost.com/blog/call-of-duty-bo7-download-size

How much faster? I have 10G, and in my experience you will very quickly get disk IO limited that it doesn't matter. You can optimize for that, but be honest - how much time you're actually going to save in lifetime.

Only place I saw 2.5G actually be beneficial is Wi-Fi 6E/7 for the APs.

I use this feature to reduce Valve's egress bill, but local transfers do seem slower than downloading from the internet. I'm not sure why. I have one device hardwired to my network switch. Maybe Steam is bottlenecked on poorly optimized disk IO code?

This is it, basically. It's a little annoying having to plan installations or wait [for ~$5 reduction in BoM]. 2.5GbE is very accessible; my LAN is 10 and WAN is 2.